Observations

Description

Frustules are thick, cylindrical and form short colonies. Valves 6-23 µm in diameter, with a mantle height of 5-14 µm. The ratio of the mantle height to valve diameter is close to 1. The mantle has straight sides. The valve face is flat. Rows of coarse round or elliptical pervalvar areolae are straight, parallel to the pervalvar axis or slightly curved to the right (dextrorse) and number 7-13 in 10 µm. There are 7-10 areolae in 10 µm within a row, some areolae may be missing. The areolae closest to the collum are often the largest. The valve face is unornamented except for one row of marginal areolae. Spines are branching at their apices. The ringleiste is solid and variable in thickness, from moderately shallow to rather deep.

Original Description

Original Description

Original Images

Cite This Page: English, J., and Potapova, M. (2011). Aulacoseira lirata. In Diatoms of the United States. Retrieved August 02, 2015, from http://westerndiatoms.colorado.edu/taxa/species/aulacoseira_lirata

Valves 6-23 µm in diameter, with a mantle height of 5-14 µm. The ratio of the mantle height to valve diameter is close to 1. Rows of coarse round or elliptical pervalvar areolae are straight and parallel to the pervalvar axis or slightly curved to the right, 7-13 in 10 µm. The areolae closest to the collum are often the largest. The valve face is flat, unornamented except for one row of marginal areolae. Spines are located at the end of each pervalvar costa. Spines are branching at the end.

Hartley, B. (1986).A check-list of the freshwater, brackish and marine diatoms of the British Isles and adjoining coastal waters.
Journal of the Marine Biological Association of the United Kingdom 66: 531-610.

Krammer, K. (1991).Morphology and taxonomy of some taxa in the genus Aulacoseira Thwaites (Bacillariophyceae). I. Aulacoseira distans and similar taxa.
Nova Hedwigia 52(1-2):89-112.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)

NADED ID: 10012

Autecology Discussion

Habits

Size Range

101-1000 µm3 (ie Amphora veneta)

Motility

non motile

Attachment

unattached

Habitat

planktonic

Colony

colonies common

EMAP Assessment

The Environmental Protection Agency (EPA) western Environmental Monitoring and Assessment Program (EMAP) study was completed during the years 2000-2004 (see citations at bottom of this page). Over 1200 streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming) were selected for sampling based on a stratified randomized design. This type of design insures that ecological resources are sampled in proportion to their actual geographical presence. Stratified randomized design also allows for estimates of stream length with a known confidence in several “condition classes” (good or least-disturbed, intermediately-disturbed, and poor or most-disturbed) for biotic condition, chemistry and habitat.

EMAP Distribution

Aulacoseira lirata

Distribution

The distribution map represents the relative abundance of this Aulacoseira lirata in the western EMAP study. Relative abundance is a measure of the proportion of cells of this species based on a "fixed count" of 300 total diatom cells counted and identified. Each of the western EMAP sample sites is shown, either with a black dot for sites where Aulacoseira lirata was not recorded, or with a red circle indicating the relative abundance of Aulacoseira lirata.

Note that the size of the proportional symbols varies between species to help show both abundant and rare species.

Scale for the map to the left

EMAP Response Plots

Aulacoseira lirata

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Aulacoseira lirata from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)STRAHLER = distribution plot of the Strahler Stream Order SLOPE = stream reach gradient (degrees)W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.PHSTVL = pH measured in a sealed syringe sample (pH units)log_COND = log concentration of specific conductivity (µS/cm)log_PTL = log concentration of total phosphorus (µg/L)log_NO3 = log concentration of nitrate (µeq/L)log_DOC = log concentration of dissolved organic carbon (mg/L)log_SIO2 = log concentration of silicon (mg/L)log_NA = log concentration of sodium (µeq/L)log_HCO3 = log concentration of the bicarbonate ion (µeq/L)EMBED = percent of the stream substrate that is embedded by sand and fine sedimentlog_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.